A novel lipase with dual localisation in Trypanosoma brucei.

Phospholipases are esterases involved in lipid catabolism. In pathogenic micro-organisms (bacteria, fungi, parasites) they often play a critical role in virulence and pathogenicity. A few phospholipases (PL) have been characterised so far at the gene and protein level in unicellular parasites including African trypanosomes (AT). They could play a role in different processes such as host-pathogen interaction, antigenic variation, intermediary metabolism. By mining the genome database of AT we found putative new phospholipase candidate genes and here we provided biochemical evidence that one of these has lipolytic activity. This protein has a unique non-canonical glycosome targeting signal responsible for its dual localisation in the cytosol and the peroxisomes-related organelles named glycosomes. We also show that this new phospholipase is excreted by these pathogens and that antibodies directed against this protein are generated during an experimental infection with T. brucei gambiense, a subspecies responsible for infection in humans. This feature makes this protein a possible tool for diagnosis.

Persistence of PCR-positive tissue in benznidazole-treated mice with negative blood parasitological and serological tests in dual infections with Trypanosoma cruzi stocks from different genotypes.

OBJECTIVES: To assess different methodologies to better define an early post-therapeutic cure criterion after benznidazole treatment in BALB/c mice following mixed infection with dual Trypanosoma cruzi genotypes. METHODS: According to the classical cure criteria, animals were classified as treated not cured (TNC = 76.4%), treated cured (TC = 12.5%) and dissociated (DIS = 11.1%) using parasitological [fresh blood examination (FBE), blood culture (BC) and blood PCR] and serological methods [conventional serology (CS-ELISA) and non-conventional serology (NCS-FC-ALTA)]. Tissues were also evaluated by PCR. RESULTS: FBE was able to detect patent parasitaemia in only 18.1% of TNC and therapeutic failure was detected in 79.1% and 97.2% of TNC by BC and blood PCR, respectively. CS-ELISA should not be used before 3 months after treatment since it may lead to false-negative results. At 3 months after treatment with benznidazole, NCS-FC-ALTA was more efficient for categorizing the groups of treated mice. In the TNC group, although a decreased frequency of PCR-positive tissue was observed in several host tissues, increased positivity was also observed, despite the T. cruzi genotype combination. All TC animals presented at least two positive tissue-PCR results. CONCLUSIONS: Our results confirm that NSC-FC-ALTA and blood PCR are the most suitable methods to early detect therapeutic failure in acute murine T. cruzi infection. Additionally, our data show that BC positivity is highly dependent upon the T. cruzi genotype combination. Moreover, our findings demonstrated that PCR tests performed on tissues from animals considered cured after benznidazole treatment still detected T. cruzi DNA, most probably indicating residual infection.

Plasmodium telomeres: a pathogen's perspective.

New data on the organization of plasmodial telomeres has recently become available. Telomeres form clusters of four to seven heterologous chromosome ends at the nuclear periphery in asexual and sexual parasite stages. This subnuclear compartment promotes gene conversion between members of subtelomeric virulence factor genes in heterologous chromosomes resulting in diversity of antigenic and adhesive phenotypes. This has important implications for parasite survival.

Peritoneal effusion in a dog secondary to visceral mast cell tumor. A case report.

BACKGROUND: Mast cell tumor, one of the most common skin tumors in dogs, may also be found in visceral sites (mainly spleen and liver). When a visceral mast cell tumor is present, neoplastic mast cells may be found in any effusion secondary to the tumor. Therefore, the diagnosis may be made by cytologic analysis of the effusion. CASE: An 8-year-old, spayed, female Siberian husky presented with a peritoneal effusion secondary to a visceral mast cell tumor. Seven months earlier, the dog had presented with a cutaneous nodule diagnosed as a well-differentiated mast cell tumor. The peritoneal fluid was classified as a transudate. Numerous neoplastic mast cells were found in the effusion. Although the mast cell tumor presented with characteristics of the well-differentiated tumor, its biologic behavior was that of a malignant tumor. CONCLUSION: Care should be taken to evaluate the prognosis of mast cell tumors in dogs since their biologic behavior is extremely variable.

The Drosophila homologue of the 64 kDa subunit of cleavage stimulation factor interacts with the 77 kDa subunit encoded by the suppressor of forked gene.

During mRNA 3' end formation, cleavage stimulation factor (CstF) binds to a GU-rich sequence downstream from the polyadenylation site and helps to stabilise the binding of cleavage-polyadenylation specificity factor (CPSF) to the upstream poly-adenylation sequence (AAUAAA). The 64 kDa subunit of CstF (CstF-64) contains an RNA binding domain and is responsible for the RNA binding activity of CstF. It interacts with CstF-77, which in turn interacts with CPSF. The Drosophila suppressor of forked gene encodes a homologue of CstF-77, and mutations in it affect mRNA 3' end formation in vivo. A Drosophila homologue for CstF-64 has now been isolated, both through homology with the human protein and through protein-protein interaction in yeast with the suppressor of forked gene product. Alignment of CstF-64 homologues shows that the proteins have a conserved N-terminal 200 amino acids, the first half of which is the RNA binding domain with the second half likely to contain the CstF-77 interaction domain; a central region variable in length and rich in glycine, proline and glutamine residues and containing an unusual degenerate repeat motif; and then a conserved C-terminal 50 amino acids. In Drosophila, the CstF-64 gene has a single 63 bp intron, is transcribed throughout development and probably corresponds to l(3)91Cd.

Collagen dysplasia (cutaneous asthenia) in a cat.

Hereditary collagen dysplasias comprise a complex group of connective-tissue disorders that result in the reduced tensile strength of affected tissues. These processes are called cutaneous asthenia in the skin of dogs and cats. We report here the case of a crossbred male cat, aged 6 months, that presented with two skin wounds in the region of the right thorax and right iliac tuberosity. The skin of these regions and of the animal's dorsum was hyperextensible, smooth to the touch, and easily torn with minor trauma. Microscopic examination of skin samples revealed reduced dermal connective tissue consisting of shortened and fragmented collagen fibers. Normal fibers were intermingled with altered fibers. Ultrastructural changes in collagen fibers included disorientation of fibrils within the same bundle, marked spacing differences, and variation in the diameter of transverse sections. The fibrils maintained the transverse striations characteristic of normal collagen.

Características anatomoclínicas dos linfomas caninos na regiäo de Botucatu, Säo Paulo / Clinicopathological aspects of canine lymphoma in Botucatu region, Säo Paulo, Brazil

Estudaram-se as características anatomoclínicas dos linfomas em cäes da regiäo de Botucatu, Säo Paulo. O material utilizado foi colhido de 34 cäes portadores de linfoma maligno, dos quais nove eram da raça Pastor-Alemäo, nove sem raça definida, cinco da raça Boxer, três animais da raça Dobermann e oito outros cada um de uma raça, 68 por cento deles machos. A idade variou de 1 a 13 anos, com média de 6,2 anos. O estabelecimento do estádio dos linfomas foi baseado nos critérios estabelecidos pela Organizaçäo Mundial da Saúde. No momento do diagnóstico, 32 animais apresentavam-se nos estádios clínicos III, IV ou V. Apenas dois foram enquadrados no estádio II. A forma anatômica mais freqüente foi a multicêntrica, diagnosticada em 31 animais. A forma tímica, diagnosticada em dois animais, e a disgestiva, em um animal, foram as outras anatômicas encontradas

[Analysis of the efficacy of the maternal breast-feeding incentive program in a peripheric district of Belo Horizonte (Brazil): 1980/1986/1992]. / Análise da eficácia do Programa de Incentivo ao Aleitamento Materno em um bairro periférico de Belo Horizonte (Brasil): 1980/1986/1992.

Three institutions worked together in order to combat early weaning in a peripheric district of Belo Horizonte (Brazil): the Department of Pediatrics of the Faculty of Medicine (Federal University of Minas Gerais), the Secretary of Health of Belo Horizonte and a Brazilian assistential institution ("LBA"). One initial survey, in 1980, documented breast-feeding practices in this community, when there were no systematized actions of incentive to human milk, at local or national levels. Two similar surveys were also conducted, in 1986 and in 1992. In each one, 152 mothers with children under two years old were randomly selected and interviewed. The results showed significant progress in the breast-feeding period in the first six years, and a stabilization between 1986 and 1992. For example: if only 39.0% of the children received human milk for six months or more in 1980, 54.3% received it in 1986 and 52.4% in 1992. In 1980, 80.6% of the children were nourished with cow's milk before three months of age, to 56.5% in 1986 and 56.3% in 1992. Prenatal influence to increase the level of breast-feeding has always been weak. Besides, a reflux was detected in the last few years with regard to the participation of the maternity hospital in the educative process.

Hemangioma peri-duodenal em equino: descriçäo de um caso / Peri-duodenal hemangiona in equine: a case report

Descreve-se um caso de hemangioma cavernoso peri-duodenal, levando a um quadro de obstruçäo intestinal, em um equino Mangalarga, fêmea, com nove anos de idade, acompanhado de histórico de óbito após quadro de cólica resistente à terapia convencional. A necropsia, observou-se intensa dilataçäo gástrica, duodeno envolto por tecido vermelho enegrecido, medindo aproximadamente 40 cm de comprimento, com intensa compressäo da luz do órgäo. O exame histopatológico revelou espaços vasculares contendo eritrócitos, delimitados por uma camada simples de células endoteliais bem diferenciadas, com tecido conjuntivo interpondo-se entre os mesmos, permitindo o diagnóstico de hemangioma cavernoso

Meningoencefalite granulomatosa em cäo / Granulomatous meningoencephalitis in a dog

A Meningoencefalite Granulomatosa (MEG) é um processo inflamatório näo supurativo do Sistema Nervoso Central (SNC). A MEG tem sido descrita desde 1972, e uma grande variedade de termos já foi usada para designar tal doença (THOMAS; EGER14, 1989). Este trabalho tem o objetivo de relatar o caso de um cäo, fêmea, da raça Dachshund, com 3 anos e 8 meses de idade, que foi encaminhado ao Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia, UNESP, Botucatu, com quadro de incoordenaçäo havia 10 dias, evoluindo para tremores e desvio lateral da cabeça. Após exame clínico e constatando-se a irreversabilidade do processo, o animal foi submetido à eutanásia. A necrópsia revelou extensa área de leucomalácia, e os estudos histopatológicos mostraram tratar-se de MEG, doença de extrema controvérsia e rara ocorrência na literatura compulsada